C/2024 E1 (Weirzchos)
The majority of impact craters on the Moon formed during the late heavy bombardment, a hotly-debated theory of a cataclysmic small-body pounding of the planets and the Moon some 4.1 to 3.8 billion years ago (the Moon is believed to have formed around 4.5 billion years ago). Whether or not scientific consensus is ultimately reached, there are thousands of craters – the more youthful examples having formed in the past billion years or so (during the Copernican geological epoch) – on the craggy lunar surface, accessible through amateur equipment.
The pre-Nectarian age is the oldest of the Moon’s geological periods, dating from roughly 4.5 to 3.9 billion years ago, before the Nectaris Basin was blasted out by a huge impact. Many large and well-known formations in the famous southern uplands formed during this period, including the vast walled plain Deslandres (diameter 234 km), on the south-eastern shore of Mare Nubium, and Janssen (190 km), thought to be 4 billion years old, near the south-eastern limb. The former is barely recognisable under high illumination, being in such a battered and eroded state; indeed until 1948 it was unnamed or informally called ‘Hell-plain’ (after the 33-kilometre crater Hell that lies within it).
South of Deslandres lies Clavius, at 231 kilometres in diameter it is the second largest crater on the Moon’s visible surface. Clavius is a few million years younger, from just before the Imbrium epoch (3.85 to 3.2 billion years ago), named for the monstrous Imbrium Basin (Mare Imbrium or Sea of Rains) formed around 3.9 billion years ago. Amateurs can see for themselves the evidence of their ancient nature in their degradation, being covered in smaller craters strewn with rubble.
The Imbrium epoch, lasting until 3.2 billion yers ago, saw the formation of the Crisium Basin and the impacts that lead to Maria Tranquillity, Serenitatis and Fecunditatis. Notable craters of this period include dark-floored Plato and Archimedes. Scrutinising the latter gives a good example of Superimposition, overlaying of one surface type on another. I can do no better than give you past Moonwatch writer Bill Leatherbarrow’s comments: “Archimedes lies on the floor of Mare Imbrium, so it clearly formed after the Imbrium basin. However, Archimedes has subsequently been embayed and flooded by the lavas that created Mare Imbrium itself, so those lavas must be younger than the crater. Finally, the flooded floor of Archimedes is peppered with a rash of small crater pits, and therefore those features must in turn be younger than the lavas that flooded the floor.” Heading back to Deslandres, its complex floor includes evidence of subsequent impacts, including crater Hell (32 km) and its array of nearly 20 named craterlets. These includes Hell Q, a relatively fresh four-kilometre crater with a bright ejecta blanket called Cassini’s Bright Spot. At full Moon, this feature is very bright. This leads us nicely to the opposite end of the Moon’s geological past and its younger impact craters.
Youthful Tycho
If the location and ancient characteristics of Deslandres need telescopic confirmation, then the location and nature of more youthful craters are apparent through binoculars or even with the naked eye.
Check out the southerly regions of an eight-day-old gibbous Moon through binoculars and the crater Tycho (86 km), located also in the southern uplands, is easy to see. Tycho is relatively young, believe to have formed perhaps just 100 million years back. It is the best example of a rayed crater, with a prominent system of bright rays of ejecta material spewed out by the impact that formed it. At full Moon, the rays are spectacularly seen with the naked eye. Through a small telescope, Tycho also displays youthful clues; well-defined walls and a pristine central peak.
Dazzling Aristarchus, mighty Copernicus and Kepler, formed from impacts believed to have occurred 450 and 800 million years ago, respectively. All three are great examples of rayed craters and are relatively youthful.
There are more than 2 billion years of lunar history I have yet to mention. This is called the Eratosthenian period, the longest on the lunar geological scale running from 3.2 to 1.1 million years ago. It is named for impact crater Eratosthenes, which is neither significantly eroded nor possessed of a system of rays.
COMETWATCH
Comet C/2024 E1 (Weirzchos) was discovered on 3 March 2024 by Kacper W.Weirzchos of the Mount Lemmon Observatory, Tuscan, Arizona. At the time of discovery, the comet shone at magnitude +20 was located at 8 astronomical units (AU) from the Sun. Investigations into the orbit showed that it had originated from an aphelion point (farthest distance from the Sun) of ~42,000 AU, placing it within the Oort cloud.
Its journey to the inner Solar System has taken around 3 million years and, after passing perihelion, the comet will eventually be ejected from the Solar System on a hyperbolic orbit. The comet passed Venus at just 0.2 AU on 1 January 2026, reached perihelion (closest to the Sun) on 20 January 2026 at 0.57 AU, and approached Earth at 1 AU on 17 February 2026.
Observing Prospects
C/2024 E1 (Weirzchos) will be past its peak brightness by the time the Moon is out of the way from 11 March, but it should still be readily visible to observers even with a small telescope. The comet could be brighter than predictions and an outburst post-perihelion could elevate the magnitude rapidly, by factors in the hundreds. The comet will be well placed in the early-evening sky, moving from Eridanus and into Taurus.
C/2024 E1 (WEIRZCHOS)
DATE
RA
DEC
MAG
11-3-26
03h 33m 15s
–02° 48' 21"
+10.0
17-3-26
03h 55m 43s
+02° 39' 57"
+10.2
23-3-26
04h 15m 06s
+07° 09' 59"
+10.5
How to use this map
Face south, holding the star map with north at the top in front of you – the lower half of the map represents the part of the sky you are facing.
DATE TIME (UT)
TYPE OF EVENT
2
13:00
Regulus is 0.4° south of the Moon (occn. N. half of China, most of Russia) Full Moon; total eclipse of the Moon, North America, Australasia, Japan, China, India Mercury is at inferior conjunction Antares is 0.7° north of the Moon (occn. southernmost Polynesia) Jupiter is stationary Last Quarter Moon Dwarf planet Pluto is 1° south of the Moon (occn. parts of Asia, S.E. Russia) Mercury is 2° north of the Moon Mars is 1.5° south of the Moon New Moon Venus is 5° south of the Moon Vernal Equinox Neptune is in conjunction with the Sun Uranus is 5° south of the Moon Saturn is in conjunction with the Sun
3
12:00
7
11:00
10
12:00
11 11
03:00 09:39
15
01:00
17 17 19 20 20 20 23 25 25 26 29
14:00 22:00 01:23 13:00 15:00 11:00 08:00 09:00 19:18 12:00 01:00
First Quarter Moon Jupiter is 4° south of the Moon British Summer Time (BST) begins Regulus is 0.3° south of the Moon (most of Europe, incl. extreme east and S.E UK, most of N. Africa).
29
20:00
MARCH
Mercury
Might be glimpsed hugging the western horizon after sunset at the start of March before passing through inferior conjunction on 7 March. Subsequently, it is out of view from the UK for a morning apparition.
Venus
Is a brilliant evening ‘star’ seen soon after sunset throughout March, making steady progress in accessibility as it pulls clear from the sunset horizon.
Mars
Unfortunately remains too deeply ensconced in the UK’s pre-dawn twilight, so the red planet is out of view all month.
Jupiter
Takes over the mantle of the brightest planet, once Venus sets. The king of the planets is a rewarding evening object on show all month until past midnight.
Saturn
Passes through conjunction with the Sun on 25 March and is out of view.
Uranus
Is an early evening object in Taurus lying within a binocular field of the Pleiades open cluster (M45).
Neptune
Is out of view this month owing to a date with the Sun at conjunction on 22 March.
Dwarf planets
Makemake, very close to opposition in Coma, together with Haumea in Boötes, are late-evening to morning imaging targets.
MOON PHASES
Rise & Set Times GMT/BST*
RISE
1
15:14 06:13
2
16:39 06:29
3
FULL MOON
18:00 06:42
Precise time
11:38
4
19:18 06:52
5
20:35 07:03
6
21:51 07:13
7
23:07 07:26
8
– 07:41
9
00:22 08:01
10
01:35 08:28
11
LAST QUARTER
02:41 09:07
09:39
12
03:36 09:59
13
04:18 11:04
14
04:48 12:19
15
05:10 13:38
16
05:27 15:00
17
05:41 16:22
18
05:52 17:44
19
NEW MOON
06:04 19:09
01:23
20
06:16 20:37
21
06:30 22:07
22
06:49 23:40
23
07:15 –
24
07:55 01:07
25
FIRST QUARTER
08:51 02:22
19:18
26
10:06 03:16
27
11:30 03:54
28
12:57 04:18
29*
15:21 05:36
30*
16:41 05:49
31*
17:59 06:01
THE MOON
LIBRATION
DATE
DEG
POSITION ANGLE
11 Mar 24 Mar
6.9° 6.9°
15° 195°
DISTANCE
DATE TIME (GMT) DISTANCE
DIAMETER
Apogee 10 Mar Perigee 22 Mar
13:44 11:41
404,386 km 366,858 km
29' 32" 32' 34"
DATE
MAG
SIZE
PHASE
RA
DEC
RISE
CULM
SET
DIST
SUN
Mar 05
–26.7
32’.2
N/A
23h 02.6m 23h 39.5m 00h 16.0m
–06° 08’ –02° 13’ +01° 44’
06:38
12:12
17:47
0.992
MERCURY
Mar 05 Mar 15
–
10”.4
02.2%
23h 14.7m 22h 43.4m 22h 43.5m
–00° 53’
06:23
12:20
18:16
0.647
VENUS
Mar 05
–3.9
10”.1
97.3%
23h 55.4m 00h 40.7m 01h 26.2m
–01° 54’
07:10
13:05
19:01
1.640
MARS
Mar 05
+1.2
4”.0
99.4%
22h 17.2m 22h 46.9m 23h 16.2m
–11° 49’ –08° 55’ —05° 52’
06:24
11:26
16:28
2.336
JUPITER
Mar 05
–2.4
42”.3
100%
07h 05.9m 07h 05.8m 07h 07.0m
+22° 55’ +22° 56’ +22° 55’
11:56
20:12
04:30
4.658
SATURN
Mar 05
+1.0
15”.9
100%
00h 11.5m 00h 15.9m 00h 20.5m
–01° 05’
07:21
13:19
19:16
10.438
URANUS
Mar 15
+5.8
03”.5
100%
03h 43.6m
+19° 34’
08:20
16:11
00:06
19.897
NEPTUNE
Mar 15
+8.0
02”.2
100%
00h 07.8m
–00° 35’
06:36
12:36
18:35
30.869
CERES
Mar 15
+9.2
00”.7
100%
01h 58.8m
+06° 29’
07:51
14:27
21:03
3.581
PLUTO
Mar 15
+14.5
00”.1
100%
20h 33.0m
–22° 49’
05:05
09:01
12:57
36.110
ERIS
Mar 15
+18.8
N/A
100%
01h 47.6m
–00° 03’
08:12
14:15
20:17
96.350
MAKEMAKE
Mar 15
+17.2
N/A
100%
13h 29.1m
+20° 40’
17:58
01:58
09:55
51.881
HAUMEA
Mar 15
+17.3
N/A
100%
14h 45.3m
+14° 10’
19:54
03:14
10:31
49.125
JUPITER MOON EVENTS
DATE
TIME
EVENT
DATE
TIME
EVENT
DATE
TIME
EVENT
1 1 1 1 1 1 1 2 2 2 3 5 6 7 8 8 8 8 9
00:28 18:54 19:53 21:36 22:39 23:16 23:52 00:56 18:56 22:17 19:24 23:14 01:26 22:30 19:15 22:33 23:27 23:52 00:35
I OcD III OcR III EcD I TrI I ShI III EcR I TrE I ShE I OcD I EcR I ShE II TrI II ShI II EcR III OcD III OcR I TrI III EcD I ShI
9 9 9 10 10 10 10 10 14 15 15 16 16 17 17 17 17 17 17
01:42 20:22 20:46 00:12 00:37 19:04 20:10 21:20 19:48 01:08 22:59 20:09 22:37 19:46 19:46 20:59 22:02 23:15 23:40
I TrE IV EcD I OcD I EcR IV EcR I ShI I TrE I ShE II OcD II EcR III OcD II ShE I OcD IV TrI I TrI I ShI I TrE I ShE IV TrE
18 19 21 23 23 23 24 24 24 24 25 26 26 30 30 30 31
20:36 21:21 22:20 19:55 20:15 22:45 00:30 21:39 22:54 23:55 22:31 20:10 21:58 19:59 22:31 22:48 23:33
I EcR III ShE II OcD II ShI II TrE II ShE I OcD I TrI I ShI I TrE I EcR III TrE III ShI II TrI II ShI II TrE I TrI
All times GMT. KEY: I Io; II Europa; III Ganymede; IV Callisto. TrI and TrE transit start and end; ShI and ShE shadow-transit start and end; EcD and EcR/OcD and OcR eclipse/occultation disappearance and reappearance.
GRS transits
DATE
TIME
1 2 4 4 6 9 9 11 13 16 16 18 21 21 23 25 28 30
23:16 19:08 00:55 20:46 22:25 00:03 19:55 21:34 23:12 00:51 20:42 22:21 00:01 19:51 21:30 23:09 20:39 22:18
Events based on an estimated mid- month GRS system II longitude of 83°. Times in GMT.
STF 1561 Ursae Majoris
Three degrees south-southwest of the magnitude +3.7 red giant star chi Ursae Majoris (UMa) and exactly equidistant between 59 and 60 UMa is STF 1561. This double is a pair of dwarf stars of spectral types G0 and K2 that lie at a mean distance of 75.8 light years. Whilst the parallaxes of the stars are similar, the errors in those measurements mean that they may not be gravitationally bound to each other. Hopefully the next Gaia catalogue, DR4, due later this year, will resolve the status of the system.
STF 1561 was discovered by William Herschel in 1782, when the stars (magnitudes +6.5 and +8.2) were at position angle (PA) 270 degrees and 12.5 arc seconds apart. I measured them in 2001 with the Cambridge 8-inch (200 mm) refractor, finding PA and separation as 250 degrees and 9.0 arc seconds. If they are a binary system, then a preliminary orbit of 2,100 years has recently been computed.
Baron Dembowski, using his 7.5-inch Merz refractor in 1863, found the stars were coloured white and ashen, and then, in another observation four years later, he noted light-yellow and olive. More recently, Sissy Haas recorded gold and peach-white. There are a number of optical companions, the closest of which are magnitude +12.1 and +9.5 stars at separations of 61 and 177 arc seconds, respectively, but in each case the distances are changing rapidly owing to the proper motion of stars A and B, which is close to 0.6 arc second per year.
Bob Argyle
Semi-regular
UX Dra following the script
The semi-regular variable UX Draconis is a bit ‘out of the way’. It lies in a relatively bland area of sky, close to where the constellations of Ursa Minor, Draco and Cepheus meet. Being located at declination +76 degrees does, however, mean that it is circumpolar from the UK and can be observed at any time of the night.
The catalogued magnitude range of UX Dra is +5.9 to +7.1. This is, however, a V filter magnitude range and visual observers see a brightness range typically about half a magnitude fainter. Hence, it is always important to take into account the colour sensitivity of the ‘instrument’ that was used when interpreting reported brightness ranges. The photographic plates used in the early decades of astronomical imaging were somewhat less sensitive to red light than are our eyes. As a result, the magnitude ranges quoted in early variable star catalogues for semi-regular variables could be a magnitude or more fainter than are seen visually.
The accompanying light-curve shows observations submitted to the BAA Variable Star section database by Chris Watkins between early 2022 and early 2025. These measurements were made using a CMOS chip with a green filter. The overall magnitude range during these three years was 0.8 magnitudes, although for most of the time it was closer to 0.5 magnitudes. The ups and downs in brightness do appear to be more or less in line with the catalogued period of 175 days. Long-term analyses have suggested the presence of a secondary period of around 334 days.
UX Dra is a red giant star. Its spectrum shows it to be relatively rich in carbon compared with most other red giants. As is the case for other semi-regular variables, the brightness fluctuations of UX Dra are primarily due to pulsations in the star’s outer layers that cause the star’s the surface temperature to rise and fall as each cycle progresses.
Tracie Louise Heywood
Eclipse mid-times (UT):
RZ Cas (Duration 4.8 hours): February 28d 22.0h, March 6d 21.5h, 12d 20.9h, 18d 20.3h, 24d 19.8h, 30d 19.2h, 31d 23.9h. Beta Lyrae (primary): March 3–5, 16–18, 29–31. Beta Persei (Duration 10 hours): February 24d 22.9h, 27d 19.8h, March 19d 21.5h.
Binocular Mira Variables:
Rising : X Oph, R Ser, S UMa. Maxima : R Ari (early March, average peak mag. +8.2), omicron Cet (mid, +3.4), T Her (mid, +8.0), R Gem (mid, +7.1), RT Cyg (late, +7.3). Fading : U Ari.
Early spring’s diverse deep-sky
It does not have to be all about galaxies at this time of the year, as a wide range of classes of denizens of the deep sky is on show, writes Mark Armstrong .
NGC 4361
RA 12h 24m 30s
DEC –18° 47' 02"
MAG +10.9
SIZE 1.9' × 1.9'
IC 405: The Flaming Star Nebula
As astronomical darkness descends at about 20:00 GMT mid-month, the galaxy fields of the likes of Leo and Ursa Major are climbing in the eastern sky. If you are fast out of the observing blocks you can still enjoy the great nebulae located in Orion, but we are headed to Auriga, a great constellation primarily of the winter sky, led by the bright star Capella, which stands tall to the south.
The Flaming Star Nebula (IC 405, Sh2-229 and Caldwell 31) is a huge area of combined red emission and blue reflection nebulosity. The nebula’s illuminating powerhouse is the eruptive variable star AE Aurigae (Aur), a massive type-O star that is unleashing torrents of ionising radiation. The image to the right shows the star right of centre.
Widefield images show a main area east to west orientated, which spans about a degree long and half a degree deep. A long tapering finger of nebulosity extends a further degree south from the western end. The main area is a marvellous combination of diffuse and rippling red emission nebulae contrasting with lanes of blue, from carbon-rich dust reflecting AE’s blue light.
A 100–150 mm telescope can detect some wispy nebulosity when working at low powers. AE Aur varies between around magnitude +5.7 and +6.1, and so it is an easy binocular object lying some 4.2 degrees east-northeast of iota (ι) Aur (mag. +2.7).
THE FLAMING STAR NEBULA (IC 405)
RA 05h 14m 32s +34° 10' 00"
DEC
MAG –
SIZE 1.4° × 1.0°
Globular NGC 2149: the Intergalactic Wanderer
The rather barren constellation of Lynx shares its western boundary with Auriga. Lurking in its south-western corner is the remarkable globular cluster NGC 2419 (Caldwell 25), its most well-known deep-sky target. This extremely remote globular cluster is thought to be located an amazing 275,000 and 300,000 light years distant from the Solar System and galactic centre, respectively. For this reason its nickname is the Intergalactic Wanderer.
A 100 mm (4-inch) telescope can track it down lying seven degrees north of Castor (alpha [α] Geminorum), but you will see it as just an unresolved haze, with perhaps a 300 mm (12-inch) telescope needed to reveal a granular texture. NGC 2419 shines at magnitude +10.3 and covers 4 arc minutes. Unspectacular owing only to its considerable distance, the Wanderer is physically massive and extremely luminous.
NGC 2419 (THE INTERGALACTIC WANDERER)
RA 07h 38m 08s +38° 52' 55" +10.3
DEC
MAG
SIZE 4'
Open cluster Messier 48
Plunge south and slightly east by around 30 degrees and we will arrive at the constellation of Hydra, the Water Snake. Here we are looking for Messier 48 (NGC 2548), a large (54') and bright (mag. +5.8) open cluster located right on Hydra’s boundary with Monoceros. M48 lies 5 degrees south of the celestial equator, restricting its optimum visibility close to its 30 degree high culmination at about 20:30 GMT.
M48 is easily snared through a pair of binoculars; sweep close to magnitude +3 zeta (ζ) Monocerotis. A small telescope at low power gives an attractive view, with around 60 stars visible. Many observers comment that M48 looks like a scaled down and fainter version of the venerated Beehive Cluster (M44), in nearby Cancer.
MESSIER 48 (NGC 2548)
RA 08h 13m 44s
DEC –05° 45' 00"
MAG +5.8
SIZE 54'
NGC 3184: the Great Bear’s face-on galaxy gem
We are of course going to visit a galaxy on our tour; two in particular. The first is NGC 3184 in Ursa Major, a fine spiral galaxy that presents face-on to our perspective. It has acquired an appropriate moniker, the Little Pinwheel Galaxy, a nod to M101, the bigger and brighter resident of Ursa Major found farther north.
NGC 3184 has a catalogued magnitude of +9.8, with a substantial apparent diameter of 6.9' × 6.8'. A 100 mm (4-inch) telescope tracks it down to Ursa Major’s southernmost reaches, close to the boundary with Leo Minor. It lies 45’ west of magnitude +3 Tania Australis (mu [μ] Ursae Majoris). All you will see is a diffuse patch of light around 4’ across; you will need a 250 - 300 mm (10- to 12-inch) telescope and high magnification to spot uneven brightness in its tightly-wound spiral arms.
NGC 3184 (LITTLE PINWHEEL GALAXY)
RA 10h 18m 17s
DEC +41° 25' 27"
MAG +9.8
SIZE 6.9' × 6.8'
Messier 60: a giant elliptical galaxy
The Virgo Cluster of Galaxies is the prime hunting ground for galaxies. The huge agglomeration of galaxies of all shapes, sizes and brightness straddles the boundary of Virgo and, to the north, Coma Berenices. The Bowl of Virgo hits the southern meridian at about midnight mid-month.
We are overwhelmingly spoilt for choice where spirals are concerned, but the field is more restricted for bright ellipticals. Giant Messier 87, the dominant galaxy of the Virgo Cluster, or M84 and M86, the close-lying pair of massive ellipticals, first spring to mind. On this occasion though let us head to the eastern outskirts of the agglomeration for Messier 60 (NGC 4649), another giant that is rated at magnitude +8.8, making it one of the brighter galaxies in the Virgo Cluster. Images show a smooth, featureless glow surrounding a noticeably brighter core, overall covering 7.2' × 6.2'
M60 can be picked up through 10 × 50 binoculars, while a 100 mm telescope shows the core and NGC 4647, M60’s delightful little eleventh- magnitude spiral companion. The image to the left displays the pair’s attractive contrast.
MESSIER 60 (NGC 4649)
RA 12h 43m 40s
DEC +11° 32' 48"
MAG +8.8
SIZE 7.2' × 6.2'
Crowing about planetary NGC 4361
The southern constellation of Corvus, the Crow lies to the south of Virgo and plays host to the famous Antennae galaxies, NGC 4038 and NGC 4039. Its next well-known target is NGC 4361, a large, eleventh-magnitude planetary nebula with a circular form spanning 1.9'.
NGC 4361 is not hard to locate as it forms the apex of an upside down triangle with magnitude +2.9 Algorab (delta [δ] Corvi) and magnitude +2.6 Gienah (gamma [γ]), the northern pair of stars in Corvus’ irregular quadrilateral-shaped asterism of third-magnitude stars. Its location is betrayed as an ‘out-of-focus star’ in a small telescope, while it is obviously nebula-like peering at it at low power through a 150 mm telescope.
SMARTSCOPE CORNER
Each month Stuart Atkinson chooses a pair of excellent targets for your smartscope imaging pleasure.
M81 and M82
The night sky is full of galaxies just waiting for your Smartscope to image, but most of the bright ones are loners, misty swirls shining serenely surrounded by glittering stars but nothing else. But in Ursa Major, just off the bowl of the asterism known as The Plough, lies a pair of galaxies so close together that they both fit easily in even the narrowest Smartscope field of view. M81 and M82 are magnitudes +6.7 and +8, respectively, and lie around 12 million light years away. As you begin to image them you will soon see that M81 is a big, beautiful, grey-white spiral, with arms that curl away gracefully from its bright silvery centre. Much smaller M82 is an edge-on galaxy and, as its image builds up on your screen, you will be struck by how mottled it appears, with clumps of orange and red along its length and a feathery centre that make it look more like an exploding comedy cheroot than a glittering whirlpool of suns. No surprise then that its nickname is ‘The Cigar Galaxy’.
The Owl Nebula (M97)
After imaging bright M81 and M82 it is time for a much more challenging object! Beneath the bowl of the Plough, a quarter of the way from Merak to Phecda, lies M97, ‘the Owl Nebula’. Only slightly brighter than magnitude +10, this planetary nebula, which lies 1,700 light years away, is a much, much smaller target than either M81 or M82. At first you will just think you are photographing an out-of-focus star, but as your image builds up you will see two small, dark patches appearing within the disc, and eventually you will understand why M97 was given its name: it really does look like the face of a cosmic owl, staring at us from the depths of space.
Polar ring galaxy NGC 2685
by Owen Brazell
NGC 2685
RA 08h 55m 35s +58° 44' 03" +12.2 (B) 4.4' × 2.3'
DEC
MAG
SIZE
NGC 2685 is an interesting lenticular galaxy in Ursa Major discovered in 1882 by Wilhelm Tempel using an 11-inch refractor at the Arcetri Observatory in Florence, Italy. NGC 2685 is also a rare polar ring galaxy, with a ring of stars lying at right angles to the plane of the galaxy. They are thought to form when a disc galaxy interacts with another galaxy.
NGC 2685 is of great scientific interest as it is one of the closest polar ring galaxies, lying some 43 million light years from us. At this distance then the disc is likely to be about 50,000 light years across, about half the size of our Milky Way Galaxy. Additionally, NGC 2685 sports a Seyfert- II active galactic nucleus (AGN), although it has also been classified as a low-ionisation nuclear emission-line region (LINER) AGN.
NGC 2685 is not that difficult to see and should be visible edge-on. The venerable Webb Society Deep-Sky Observer's Handbook (WSDSOH) Vol. 4 suggests it is very faint in 210 mm, while the NSOG suggests using 200– 250 mm telescopes to see it and 400–450 mm telescopes to see any detail. The polar ring is beyond range visually.
How to use this map
Face north, holding the star map with south at the top in front of you – the lower half represents the part of the sky you are facing.
Mercury
Can be viewed in the pre-dawn sky from around mid month on its way to greatest western elongation in early April.
Venus
Burns bright but is a bit of an horizon-hugger all month in the early-evening sky.
Mars
Emerges faint and lowly in the pre-dawn sky towards the end of the month.
Jupiter
Is well placed all month as a brilliant evening object among the stars of Gemini.
Saturn
Is in conjunction with the Sun and out of view.
Uranus
Lies in Taurus as an early evening binocular target that is best observed early in the month.
Neptune
Has a date with the Sun and is out of view all month.